Switching Energy Barrier Study of Toggle MRAM Using a Novel Pulse Technique

We present a complete study of the influence of thermal activation on the DW mode, the toggle mode, and on the separate first and second pulses of the toggle sequence. To obtain these results, we developed a novel technique that employs a train of three-pulse packets. We found good agreement with a single energy barrier (E_b) thermal activation model for both the DW and toggle modes, indicating excellent bit switching quality. We also measured the E_b vs. bit size with no changes in the material stack, and found that E_b >70 k_bT to below 0.1 um, which is sufficient stability for scaling toggle MRAM to beyond the 65 nm CMOS node.